pro·pane (pr??p?n?)n. A colorless gas, C3H8, found in natural gas and petroleum and widely used as a fuel.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.propane (?pr??pe?n) n (Elements & Compounds) a colourless flammable gaseous alkane found in petroleum and used as a fuel. Formula: CH3CH2CH3[C19: from propionic acid + -ane]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014pro?pane (?pro? pe?n) n. a colorless, flammable gas, C3H8, of the alkane series, occurring in petroleum and natural gas: used chiefly as a fuel and in organic synthesis. [1866; prop(ionic acid) + -ane] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.pro·pane (pr??p?n?) A colorless, gaseous hydrocarbon, C3H8, found in petroleum and natural gas. It is widely used as a fuel.The American Heritage® Student Science Dictionary, Second Edition. Copyright © 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.